On my new S&W Shield 45 I noticed an odd machining pattern on the area that the bullet pushes up against. I have never seen this before on other semi-auto pistols. I attached pictures and think it is kind of odd.

Your take?



and....

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Vern

That's being discussed before, and it is normal, all shield 45 has those machining mark, why ? I don't know, what for ? no idea, all I care is my gun fires every time I pull the trigger. I don't spend too much time staring at the gun trying to find imperfections.


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M&P 9, Shield9.

If only the search function on these boards worked, repetitive questions like this could be answered without another post. But it is not to be so.

I read in previous posts that the purpose for the cuts is to help push the top round in the mag rearward as the slide retracts to make sure the round has enough room to feed properly when the slide comes forward.

Don't know why it is apparently only on the Shield .45.

Normal


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Much bigger round, cycling through a SLIGHTLY larger platform and its made for some MUCH tighter tolerances in that area the shell has to move through. Apparently needs all the help it can get.

Seemed fairly ingenious to me.

The cuts are a design element to improve function. When the slide glides (rhymed) over the 45 round the cuts allow for a smoother action, has less drag. It may also help set the next round back for a more positive clambering.

Sorry, but I can't buy that concept.
The recoil initially could move the rounds in the magazine more forward, except for the fact that this "ridge" puts pressure down on the stack of bullets. Then there is the reverse inertia created by the slide slamming back against the back of the pistol. At that point any slight movement forward of any rounds in the magazine would create a marked rearward position of the bullets in the magazine, except for the fact that the "ridge" is now at it's peak pressure on the top of the rounds in the magazine.

In the picture illustrations below it shows a SIG Sauer P320 in .45 and the S&W Shield in .45, and you will notice the SIG has an incline more aggressive than the very slight incline of the Shield. Also there is no ridges on the SIG Sauer P320 that "grab" any of the shell casing. Rather it is a more polished area that allows the slide to literally slide over the bullet(top one) in the magazine.

Search works when you know exactly what this type of ridge is actually called and that name was also included in the original "title" of the thread. I would love to not repeat questions already answered. However, I am not convinced this is a design feature built into part of their machining.

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Vern

Also this is way smoother than the way it come from the factory. I used a Dremel and a polishing wheel to smooth out some of the ridge. I cannot believe (maybe they did) that someone in engineering purposely designed in these ridges since this is a 1. critical for the slide to move smoothly backward and not be hindered by undue rub. 2. That these "ridges" are in a direct wear area and will eventually be mitigated over a few thousand rounds. If they were necessary, your pistol would soon become prone to malfunction when these wore down in normal use. After polishing it shoot exceptionally well, with no issues in feed or extraction whatsoever.

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Vern

What we do know, is that it's not a mistake in machining, not a worn tool, and that they've been there, since the release of the Shield, which is around a year ago. Since mine has worked flawlessly those machined ridges, I'm not going to dremel them off. Would be nice to know the exact reason though.

I think the Engineer at S&W that designed those worked previously for Frito-Lay in their potato chip division, specifically Ruffles potato chips.... Everyone knows "Ruffles have ridges".

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Vern

The hard steel of the slide rubbing on the soft brass of the cartridges should not cause the steel to wear down any time soon. While this is an odd design (it's unique among my seven slide-operated semi-autos), it has worked well in my Shield .45 for 1600 rounds. It shows no signs of wear. I can only assume that S&W engineers found something in their testing of the Shield .45 prototypes that caused them to deviate from the smooth versions found in previous Shields and other M&P pistols.

I hope you haven't voided your warranty by taking a Dremel to your slide. However, if it continues to function well for the next 10,000 rounds, it won't really matter.

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What, me worry?

True enough about brass cases, but would not be too sure about cheaper steel case ammo. Everything will wear, even steel that is abraded by brass. Granite will wear when enough time and water is applied.

I don't see any issues with feed or functioning with this after I "smoothed" out the ridges just a bit. At least I didn't take a disc grinder to it LOL. Ridges are still there, but for the life of me I can't imagine that they were some design feature.

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Vern

To get an idea of how well the search feature works, look at the panel at the end of each thread, "Similar Threads". This appears to be an auto search based at least on the original post's title and/or content. Despite the fact that the subject of this thread has been covered four or five times in the past year, not one of the "Similar Threads" refers to the Shield .45 problem under discussion.

I have noticed this is true almost every time I have looked at that end panel. I have conditioned myself not to bother with it or the search function, because unless you can hit the exact same terms, which is hardly ever possible, the searches are way too narrow to return useful results.

Maybe I need a tutorial on searching or have just become lazy because so many good search engines out there easily return useful information. I do believe it is accurate to say most search programming on these type of boards is weak and frustrating to use, therefore not used successfully very often.

You could take the exact same search terms that returned nothing on one of these gun boards, put it in Google and get pages of similar topics, even in the same board originally queried.

The repititive nature of posts covering the same topics is the result of either poster laziness for not "searching" for their answer first, or it is the result of a poster searching this board and finding nothing despite the fact there are other posts covering the same topic on this board.

Or, someone just wants to complain or argue.